1 . Field of the Invention
The present invention relates to high performance polynorbornene materials and, more particularly, to norbornene monomers with cross-linkable groups and their derivatives
2. Description of the Related Art
Polynorbornene and its derivative were the first commercial products produced from ring-opening metathesis polymerization (ROMP) and were important elastomers. Due to the high transparency, improved impact resistance, wide using temperature range and good mechanical and processing properties, polynorbornene and their derivatives were widely applied in shape-memory polymers, lighting devices, machines, electric components, pipe fittings and food packing. In addition, their derivatives, such as polymers containing acid and ester were further used as photo resists.
Metathesis polymerization of olefins was an important process for polymerization, especially the living ring-opening metathesis polymerization with organometallic catalyst. The polymerization process started with ring-opening reaction of cycloalkene in the presence of organometallic catalyst. The reaction continued until cycloalkenyl monomers depleted or the catalysts lost their activities. Advantageously, such polymerization produced less side products during the reaction, and changing the catalyst type or substituted group of the monomers may obtain polymer or co-polymer with different physical properties. Furthermore, their active polymerization characters further facilitated preparation of functional block co-polymers.
Increasing interest in ring-opening metathesis polymerization of norbornene derivatives containing functional groups has developed over recent years with the aim of obtaining polymer structures with attractive properties. Besides of excellent transparency and mechanical properties, cross-linkable polymers have found a wide demand in the domain of interpenetrating polymer networks, non-linear optic materials, and the formation of more thermally and chemically resistant materials.
One of the most widely employed cross-linkable side chains was the methacryloyl group, which polymerizes both thermally and photochemically in the presence of free-radical initiators and photosensitizers, respectively. In prior arts, monomers with poly functional groups easily perform multi-reaction with organic metals to form insoluble gel or cross-linking products. So the use of ring-opening metathesis polymerization (ROMP) in the formation of theses cross-linkable polymers has been limited. 1
It is reported that in the ring-opening metathesis polymerization of 5-methacryloyl-1-cyclooctene, gel formation was observed when Ru catalyst I was used without methyl inhibitors during polymerization.
Therefore, the present invention provided norbornene monomers with cross-linkable olefin group, norbornene monomers with cross-linkable epoxy group, and polymers derived from these two monomers, which may further prepare cross-linked hybrid materials.